Machine for cutting designs, letters, etc.



Jan. 15, 1929. 1,698,833

T. TOWNSEND MACHINE FOR CUTTING DESIGNS, LETTERS, ETC

Original Filed July 8, 1924 v 2 Sheets-Sheet l FIG.1.

Jan. 15; 1929.

7 1,698,833 'r. TOWNSEND MACHINE FOR CUTTING DESIGNS, LETTERS, ETC

r inal Filed July 8, 1924 2 Sheets-Sheet 2 I Fl 13.3

' I ,5 A? //VVE/V70R WITNESSES M Patented Jan. 15, 1929.

UNITED STATES P ATE NT OFFICE THOMAS TOWNSEND," OF"PITTSBURGH,PENNSYLVANIA, ASSIGNOR F ONE-HALF TO HARRY F. ANDERSON, OF MARION,INDIANA, AND ONE-HALF TO JAMES BOYCE, OF

HOLLAND, MICHIGAN.

' MACHINE FOR CUTTING DESIGNS, LETTERS, ETC.

Application filed July 8, 1924. Serial No. 724,793.

In the manufacture of illuminated signs, the outlines of letters,figures or designs are formed through some opaque material, generallysheet metal. It has heretofore been the practice to cut'the outlines bymeans of shears, or ifthe metal sheet is thick, it has been necessary toemploy cold chisels. As the outlines-are, infpart at least, irregular,there will be a bending ofthe edges of metal in turning the shears toform such. irregular outlines, and when employing cold chisels, theedges of the sheet will be more or less bent. In the completed-sign theedges of the opaque portion should be fitted closely 5 against theglasssheet back of'the opaque sheet, and hence it is the practice to.flatten the sheet in a press or by pressing it between rolls after theoutline has been formed, to eliminate thebendsor kinks. But as the metalis more or lessstretchedwhen being bent by the shears or chisel, suchrolling will only partially flatten the edges.

The object of the invention as described herein is to provide meanswhereby the outlines desired be cut in a sheet without any bending orstretching of the metal. The invention is hereinafter more fullydescribed and: claimed.

In the accompanying .drawings forming a part of'this specification, Fig.lis an end elevation of the cutting mechanism claimedvherei'n:;--lii'g..2 is elevation of the opposite end of the mechanism;Fig. 3 is a top plan;

. and Fig. Lisa rear elevation of the mechanism; and Figs. 5 and 6 areside and edge views of a cutter.

In the practice of'the invention the cutter is not only driven but isalso carried by an electric motoradapted to be shifted over the sheetoperated on the motor, which may be of any suitable construction, isenclosed in a suitable shell or casing 1 provided at its ends withbearings 2 for the shaft 3 of the armature. Tofacilitatethe' sliding ofthe motor overthe-sheet, and to maintain the axis of the armaturesubstantially parallel with the sheet, a plurality of supports areprovided. In the construction shown, three points of support areprovided, twoof such supports being in or approximately in alinementvertically with the axis of the armature shaft and the third support atone side of a line passing through the other two supports. One

' of said supports consists of a shoe formed by a. curved bar 4 havingslotted fingers 5 at its ends and held in position by bolts 6 passingthrough the slots into the shell. The other shoe in alincment with theshaft of the armamounted in an extension of the handle 10 secured tooneside of the shell or casing 1.

7 It will be apparent that by providing a support immediately adjacentthe cutter and vertically beneath the cutter axis and a plurality ofsupports disposed from said first support axially of the cutter andadapted to permit movement of the tool transversely of the axis of thecutter,- the tool may readily be pivoted about vertical axesintersecting the cutter axis. These shoes are adapted to permit movementof the tool transversely of its axis and to resist movement along theaxis so that in pivoting the tool the cutter Will roll peripherally indescribinga curve rather than slideaxially. WVith this construction itis possible to cause the cutter to describe curves of extremely shortradii.

It will be readily understood by those skilled in the art that in orderto readily out along curved lines having short radii, the cutter. shouldhave comparatively small diameter and as the cutter should be so mountedthat a portion of its edge will project below the supporting points, itsaxis of rotation is below the 'axis of the armature and hence provisionis made for transmitting motion from the armature to the cutter. In theconstruction shownherein the cutter 11 is secured on a shaft 12 mountedin a boss 13 projecting from the cover 14 of a box 15. On the inner endof the shaft 12 is secured a pinion 16 adapted to intermesh with anidler 17, the journals of which extend into openings in the box. andcover as shown in Fig. 4-; this idler intermeshes with a pinion 18secured on the shaft 3 of the armature, said shaft extending through theupper portion of the box. While the box may be secured to the shell orcasing in any suitable manner, the

construction shown has been found suitable hanging the cutter 11 securedas before stated on the shaft 12. To this overhanging portion 22 issecured one end of the bar 7 forming one of the supports of themechanism. The curved portions 8 of this bar is slotted as at 23permitting the lower portions of the cutter to project through andoperate 011 the sheet. As before stated, the curved portion 8 bears onthe surface of the sheetoperated on and provision is made for adjustingthe position of the portion 8 of the bar relative to the cutter andthereby regi'ilate the depth of cut made by the cutter. Such depth ofcut will vary in accordance with the thickness of gauge of the sheetoperated on. The adjustment of the bar 7 can be effected in any suitablemanner, as for example in the construction shown, one end of the bar 7which is resilient, is secured to the portion 22 and the desired flexureof the free portion of the bar. is effected by a screw 24 passingthrough the portion 22 and bearing on the bar as clearly shown in Figs.1 and 8. In order to facilitate the manipulation of the mechanism, it ispreferred to employ an auxiliary handle 25 preferably secured to theoverhanging portion 22 so as to be in approximate alinement with thecutter. In the construction shown, the bar 7 is secured to the portion22 by the handle, the threaded end of the latter passing through theupturned end of the bar and screwing into the portion 22.

As the outlines to be cut in a sheet have curved portions. the radii ofsome of such curved portions being small, the width of the out should begreater than the thickness of the teeth in order that the cutter may beshifted to change the direction of out. As shown in Figs. 5, 6 and 7,the teeth are approximately pyramidal in shape, the front and rearfaces, a and Z) having equal inclinations. The sides 0 and d of theteeth are, however, differently inclined as clearly shown in Fig. 7 Theside 0 of tooth 0'0 being at an obtuse angle to the side of the body ofthe cutter, while the side (Z of the tooth forms a more acute angle withthe side of the cutter. The inclination of the sides of an adjacenttooth 1 are the reverse of those of the sides of tooth m. By reason ofthedescribed inclination of adjacent teeth, the. apices will be out ofline peripherally and consequently the cut made in the sheet will permitof such shifting of the mechanism as will permit the following of curvedlines.

It will be noted that the motor 1 constitutes the major portion of theframework of the machine and is of such size as to furnish the weightrequired to make the machine steady and free from objectionablevibration in the operation of the cutter. The parts 2, 3, 14, 15, 19 and20 constitute frame means for supporting the cutter at a substantialdistance from the motor. It will be understood that in cutting a curveof short radius, the motor end of the machine is swung through a longerare than if the cutter were close to the motor; consequently the motorend of the machine may be swung and guided with the required accuracyand precision more easily than if the arc was short. 7

In cutting a curve of larger radius, as, for example, one that extendstoward the left in Fig. 3, the motor end of the machine would haverelatively little movement of translation, the handle 25 being employedto push the cutter end of the machine along the required path.

I claim herein as my invention:

1. A machine for cutting a metallic sheet comprising an electric motorwhich constitutes the major portion of the framework of the machine andfurnishes the weight required forsteadiness in operation, a relativelysmall rotary cutter frame means attached to the motor for supportingsaid cutter at a substantial distance from the motor, means forcommunicating power from the motor to the cutter, a support on saidframe means adjacent to the cutter adapted to rest on the sheet beingcut and adapted to permit the cutter to sever, the sheet, a handle onsaid frame means adjacent to said cutter for guiding the cutter end ofthe machine when the latter is turning on the sheet, two supports onsaid motor adapted to rest on the sheet being out, said supportsconstituting a threepoint support for the machine, permitting freeturning movement of the machine on the sheet, and a handle on the motorfor guiding the motor end of the machine in such turning movement.

2. A portable machine for cutting rigid sheet material comprising anelectric motor which furnishes the weight required for steadiness inoperation, a relatively small rotary cutter, frame means attached to themotor for supporting said cutter ata substantial distance from themotor, means for communicating power from the motor to the cutter, asupport on said frame means adjacent to the cutter adapted to rest onthe sheet being cut and adapted to permit the cutter to sever the sheet,a handle adjacent to said cutter for guiding the cutter end of themachine when the latter is turning on the sheet, two additional supportsadapted to rest on the sheet being out, said supports constituting athree-point support for the machine, permitting free turning movement ofthe machine on the sheet, and a handle for guiding the motor end of themachine during such turning movement. 7

In testimony whereof, I have hereunto set my hand.

THOMAS TOWNSEND.

